Question

can we get an example for convertion of mass to energy,as we get an equation of that by formula E=mc2?

Answer 1

Question:

Can we get an example for conversion of mass to energy, as we get an equation of that by formula $E = mc^2$?

Answer:

The formula $E = mc^2$ shows that matter and energy are interrelated, matter can be converted into energy and energy can be converted into mass.

$$E = mc^2$$

Where:

$E$ is Energy in Joules (J)

$m$ is mass in kilograms (kg)

$c$ is the speed of light in meters per second ($m \cdot s^{-1}$) which is $3.0 \cdot 10^8 \, m \cdot s^{-1}$

$$c^2 = (3.0 \cdot 10^8)^2 = 9 \cdot 10^{16}$$

Example:

Simplest example of mass to energy conversion is fission of Uranium-238

The results are more useful in nuclear reactions, during the fission of $1\,\mathrm{kg}$ of Uranium-235 about $6.7 \cdot 10^{10}\,\mathrm{J}$ of energy is released. Using the equation $m = E / c^2$ we get

$$m = \frac{6.7 \cdot 10^{10}}{9 \cdot 10^{16}} = 7.4 \cdot 10^{-7} \, \mathrm{kg} = 0.74\,\mathrm{mg}$$

A loss of mass of about $0.000074\%$, small but definitely measurable.